Answer:
Part A- Linear duplicated chromosomes
Part B-Anaphase
Step-by-step explanation:
Sister chromatids are duplicated copies of a single chromosome that are attached to each other and are identical. They are attached at the centromere. The sister chromatids which are linear separate at the centromere and migrate to the opposite poles.
During anaphase, the sister chromatids of each chromosome separate at the centromere with each moving towards the opposite pole. The chromatids are pulled by the shortening of the spindle fibres. Mitochondria congregate around the spindle during this movement.